CFTR and autosomal recessive disease: Cystic fibrosis is a common autosomal recessive disease caused by variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes for an ion channel, CFTR, that is involved in regulation of the water–electrolyte balance on the surface of many organ systems, including the upper and lower airways, intestine, pancreas, biliary tree, cervix, vas deferens, and sweat glands (1).